1. Field of the Invention
The present invention relates to the installation and formation of pipelines into the earth. More particularly, the present invention relates to apparatus for the support of pipelines within a trench. Additionally, the present invention relates to apparatus wherein the pipeline can be installed and welded within the trench and whereby the pipeline can be lowered into the trench in a convenient and safe manner.
2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 37 CFR 1.98
Pipelines are used to transport fluids, typically oil, gas and other petroleum products, across long distances. In the current art of installing new pipelines, the pipe is lowered into trench and laid on top of support benches, which are spaced along the length of the trench floor. The trench containing the newly-laid pipe is then backfilled normally in two stages. A layer of uniform, rock-free subsoil is introduced into the trench so that it flows around and beneath the pipe between the spaced support benches, fills up the open area between the sides of the pipe and the trench walls, and covers the pipe to a specified height over the pipe.
In the past, a variety of lifting apparatus have been utilized so as to place each of the pipes of the pipeline into the trench. Conventionally, this requires that heavy equipment be moved to the pipeline trench location so as to carry out the requisite work. The attachment of the heavy equipment, such as cranes, to the pipe of the pipeline can be a complex and time-consuming procedure. Additionally, the attachment of the cables to the pipeline can be somewhat dangerous to the person performing the connection. The pipes are extremely heavy and, if not properly attached, can be released in a dangerous manner. After the pipeline is placed within the trench, it is necessary to release the cable from the pipeline so as to allow the pipeline to remain within the trench.
Typically, during the installation of pipelines, it is necessary to weld one pipe to another pipe. This welding activity is carried out adjacent to the trench and on the surface of the earth at the trench. In order to properly weld the pipeline, a suitable rotation mechanism must be placed on the pipeline so as to allow the pipeline to be properly rotated during welding. In other circumstances, the welder must carry out a difficult and cumbersome task of utilizing the welding equipment in a manner so as to extend circumferentially around the pipe in the location between the pipeline sections. Additionally, machining is necessary on the pipes of the pipeline so as to allow a proper weld to be achieved. After the welding is completed, the heavy equipment is then required to install the welded pipeline within the trench. Once again, this is difficult, time-consuming, and potentially dangerous. A need has developed whereby the pipeline can be properly welded while supported within the trench and whereby the welded pipeline can then be easily released into the trench without the need for heavy equipment.
In the past, various patents have issued relating to the installation of pipeline into trenches. For example, U.S. Pat. No. 4,063,429, issued on Dec. 20, 1977 to E. I. Wilson, shows a pipeline retard, support and protection method wherein a fast-setting expandable foam is placed in a trench at spaced locations below and around a pipeline to increase spaced retards and support pads in situ. Each retard and/or support pad is created in the absence of forms or other foam molding means for the expanding foam. The retards may be keyed to the trench walls and base for securement.
U.S. Pat. No. 4,068,488, issued on Jan. 17, 1978 to D. G. Ball, discloses a method of backfilling pipeline trenches. The trench is backfilled by temporarily supporting the pipeline at grade in the trench on deflatable airbags spaced along the bottom of the trench. The trench is then backfilled below and around the pipe by pneumatically blowing a granular fill material into the trench first beneath the pipe and then progressively upwardly about its opposite sides to about its spring line so as to simultaneously backfill the trench and uniformly compact the fill material about the pipe without leaving any voids. The fill material is blown into the trench through a pair of opposed air ducts with upturned lower outlet ends extending into the trench on opposite sides of the pipe so that backfilling progresses upwardly on opposite sides of the pipe simultaneously. As the backfilling operation progresses along the trench and approaches each support pad, the pad is deflated and removed so that the operation can proceed uninterruptedly.
U.S. Pat. No. 4,090,686, issued on May 23, 1978 to T. G. Yarbrough, shows a pipe-laying apparatus for supporting pipe elements in an excavation during the positioning of the pipe therein and prior to the filling in of the excavation with particulate material. The device consists of an upright two-legged frame and movable pipe-supporting slides that provide for easy removal of the device from the excavation after it has supported and maintained the alignment of the pipe-like elements during the pipe-laying operation.
U.S. Pat. No. 4,197,033, issued on Apr. 8, 1980 to G. J. Gendron, shows a method of installing a pipeline by forming a ground surface below the desired grade of the pipeline, holding a pipe length at the desired grade while injecting a hardenable fluid material into a bag positioned between the pipe length and the underlying ground surface so that after the material hardens, the bag provides a temporary support for the pipe length at the proper grade. A permanent support is installed by placing hard granular material between the remainder of the underside of the pipe length and the underlying ground surface.
U.S. Pat. No. 6,250,847, issued on Jun. 26, 2001 to T. R. Bingham, provides a pipe support apparatus that includes a sleeve for being positioned along a length of a stake to be inserted into a ground surface of a trench. A sleeve projection extends outwardly from an outer surface of the sleeve. A hook extends partially about the pipeline so as to cradle a pipe. The hook operatively has an upper end and a lower end. The hook is pivotally coupled to the sleeve projection at its upper end for movement generally along a vertical plane from a lowered or engaged position to a raised or disengaged position. A handle is coupled to the hook and operatively extends upwardly therefrom for grasping and moving the hook between its engaged and disengaged positions.
U.S. Pat. No. 6,336,770, issued on Jan. 8, 2002 to K. T. Evans, discloses a pipe installation device that has opposing elongate anchor members having inside edges tapering away from a clamping end for sliding the pipe between the anchor members when the pipe is being positioned on the grade surface prior to supporting above the surface. The elongate anchor members penetrate a grade surface for holding the device upright while a clamp is secured to the rib for holding the pipe above the grade surface. The clamp is attached to the anchor member upper portion and holds the rib between clamp jaws. With the rib positioned upward and away from the pipe surface, the support devices holding the pipe are removed after the aggregate is placed within the trench and around the pipe. They are removed without displacing the pipe.
U.S. Pat. No. 6,413,018, issued on Jul. 2, 2002 to E. J. Klaymar, provides a method for supporting pipeline in a trench. The involves supporting the pipeline on specially-designed support benches at spaced intervals. The benches are designed to fail when exposed to a predetermined load. The load is placed on the benches at some point during the backfilling of the trench or when the pipeline undergoes hydrostatic testing. When the benches fail, the fill under the pipeline is compacted and thereby supports the pipeline in lieu of the support benches.
U.S. Pat. No. 7,074,305, issued on Jul. 11, 2006 to G. W. Connors, provides a pipeline support for reducing corrosion on a pipeline surface. This pipeline support comprises support fill material and a case for housing the support fill material.
It is an object of the present invention to provide a pipeline support apparatus that effectively supports a pipeline within a trench.
It is an object of the present invention to provide a pipeline support apparatus that allows welding and machining operations to carried out on the pipeline while the pipeline is in the trench.
It is another object of the present invention to provide a pipeline support apparatus that allows the pipeline to be lowered toward the bottom of the trench in a safe, convenient and efficient manner.
It is still another object of the present invention to provide a pipeline support apparatus which avoids the use of cranes and other equipment for the purpose of lowering the pipeline to the bottom of the trench.
It is still a further object of the present invention to provide a pipeline support apparatus that easy to use, easy to manufacture and relatively inexpensive.
These and other objects and advantages of the present invention will become apparent from a reading of the attached specification and appended claims.